Limitations on Towed Array Gain Imposed by a Non-Isotropic Ocean

Abstract

This study deals with the limitations imposed by ocean characteristics on hydrophone array gain and on attempts to create a syntheticaperture using towed-array measurements. The multi-element synthetic or physical aperture of a passive array operates in a non-isotropic noise field and in a medium of limited spatial coherence length. In particular, it is assumed that due to distant shipping the noise field is partially directive and imposed upon an isotropic noise background, and in the rough bounded transmitted medium many multipaths exist which are closely spaced in arrival time and arrival angle. The coherence properties of the medium are synoptically considered to be characterized by its temporal coherence and the angular uncertainty which is the inverse of the spatial coherence length.

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1990
Accession Number
AD1114343

Entities

People

  • S. Stergiopoulos

Organizations

  • SACLANT ASW Research Centre

Tags

Communities of Interest

  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Fields
  • Acoustic Scattering
  • Acoustic Signals
  • Acoustics
  • Algorithms
  • Ambient Noise
  • Broadband
  • Data Acquisition
  • Digital Data
  • Estimators
  • Frequency
  • Frequency Bands
  • Frequency Domain
  • Human Factors Engineering
  • Inverse Problems
  • Maximum Likelihood Estimation
  • Measurement
  • Military Research
  • Scattering
  • Towed Arrays
  • Wave Propagation

Fields of Study

  • Engineering

Readers

  • Acoustical Oceanography.
  • Calculus or Mathematical Analysis
  • Phased Array Antenna Design.

Technology Areas

  • Space